that's weird. did this happen from the beggining? what about frontend? do you get this error too?

Yes, it is from the beginning and it does also make the front end unavailable as well. I have to back space to get back to my plugins and disable it in order to access my site.

I found a related article that suggested this fix - and it owkred:
If the problem happens on the front end and the back-and just access the configuration.php file and line "22" where is (public $ gzip = "1" to change (Public $ gzip = "0" changing from 1 to 0 the problem will be solved if the GZIP
am able to enable the plug-in, and now I have about 5 of these errors
Strict standards: Only variables should be assigned by reference in C:\wamp\www\plugins\system\contentstats\contentstats.php on line 269

Awesome, now I am down to just one error!
Warning: Creating default object from empty value in C:\wamp\www\plugins\contentstats\com_content\com_content.php on line 686
all Stack
# Time Memory Function Location
1 0.0014 266944 {main}( ) ..\index.php:0
2 0.2336 6739704 JAdministrator->dispatch( ) ..\index.php:70
3 0.2348 6797520 JComponentHelper::renderComponent( ) ..\application.php:165
4 0.2450 6816888 JComponentHelper::executeComponent( ) ..\helper.php:335
5 0.2456 6844272 require_once( 'C:\wamp\www\administrator\components\com_contentstats\contentstats.php' ) ..\helper.php:355
6 0.2498 6975944 JControllerLegacy->execute( ) ..\contentstats.php:58
7 0.2498 6976072 StatsController->display( ) ..\legacy.php:722
8 0.2498 6976104 JControllerLegacy->display( ) ..\controller.php:24
9 0.2614 7366200 StatsViewItems->display( ) ..\legacy.php:685
10 0.2704 7663416 JViewLegacy->get( ) ..\view.html.php:56
11 0.2704 7663544 StatsModelItems->getTypes( ) ..\legacy.php:398
12 0.2705 7663832 JEventDispatcher->trigger( ) ..\items.php:216
13 0.2705 7664336 JEvent->update( ) ..\dispatcher.php:162
14 0.2705 7664824 call_user_func_array ( ) ..\event.php:71
15 0.2705 7664856 plgContentstatsCom_content->getTypes( ) ..\event.php:71

OK, thank you for your help